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Comment by burgerbrain | Hacker News Reader

This is why you always have TrueCrypt use multiple volumes. This is exactly what plausible deniability is for.

The key is to put some stuff that's reasonably embarrassing in the fake volume, like nude pictures of yourself or weird fetish porn.

That would be perjury, though. You are now a Lying Guy, not just a Fifth Amendment Guy, and no amendment will be able to save you if they figure out that you gave a hidden volume password and claimed it as the "real" and only password.

I'm not saying plausible deniability is bad, just that it would be better not to rely on technical arms races to protect fundamental rights.

The Passive Aggressive Award will go to the guy who freely gives the real password to the feds when subpoenaed, but claims it is just a hidden volume password.

You generally give them the non-hidden volume password, not the hidden volume password. This is because, unless you tell them so (or they see you using it, or have spyware on your system, etc.), there is absolutely no way to prove the existence of a hidden volume from looking at the file. There's also no way to prove that a truecrypt file does not contain a hidden volume, which leads to some interesting problems if people catch on to the existence and usage of hidden volumes (I recommend creating a hidden volume in any encrypted container just so that you can show that there's nothing hidden in it. Truecrypt doesn't support more than one hidden volume in a single file, right?).

If you do accidentally tell them, it's a bad thing. Generally, you should only take advantage of this if 1) the punishment for whatever you have in the hidden volume is bad enough that the addition of perjury charges would be like adding a single spike to an atomic bomb, or 2) you are absolutely sure that they're not going to figure out the existence of it from anything you have lying around or other people.

This is not legal advice, I'm not a lawyer.

Actually, there are ways to prove a hidden volume indirectly. For example by the file names you opened or the last modification date of a truecrypt container file. There is an article about all the small things to watch on the Truecrypt website.

My small modification:

>There is an article about all the small things to watch on the Truecrypt website.

There is an article about all the tricky things to watch for. They're not any smaller than any other booleans on your system, and with software like encase, such inconsistencies will be found.

You're right, I butchered the jargon there. By "hidden volume" I meant the volume that is hidden during normal use, whereas the conventional meaning of that term is the volume that is hidden when you give the false password. Exact opposites.

> I recommend creating a hidden volume in any encrypted container...

Do you not want the recommendees to enjoy plausible deniability? After all, if they always create a hidden volume, they could reasonably be held in contempt for refusing to give two passwords for every volume.

I've always wondered how people would answer the "Your volume is 512MB, but this truecrypt file is 2GB. Explain please". question.

I guess they can't prove that there is a hidden volume, but I thought with Truecrypt they could not prove whether a file was actually a Truecrypt volume in the first place?

In truecrypt, the volume would report 2GB, not 512MB, and you have to be careful not to put in more than the invisible limit, otherwise the hidden portion will be corrupted/overwritten.

Truecrypt can have hidden volumes, the truecrypt file may be split into 1.5gb / 0.5gb. The truecrypt file reports 2GB, but different passwords mount different the different sized volumes, hence putting in the 512MB password will mount a 512MB volume of a 2GB file.

It works the way the parent says, not the way you say.

Oh, my bad then. I guess I should look at my volumes closer. :)

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